Head-Fi.org › Forums › Equipment Forums › Dedicated Source Components › Audio-gd NFB-28
New Posts  All Forums:Forum Nav:

Audio-gd NFB-28 - Page 109

post #1621 of 1728

Thanks for the reply.

 

Quote:

Originally Posted by MadSounds View Post


I think the extra power would be getting a balanced cable for his hdxx as nfb-28's SE output is not summed and has half the total power of the balanced out (which is equal in power to nfb-29.

I was replying to a post where bassaddicted said "The only noticeable benefit of balanced connections in a headphone setup would the the extra power." and the setups being compared were the

Modi Multibit + C-2 vs the NFB-1 amp and dac. It seems that the power from the  NFB28 and 29 is the same, so I was extrapolating bassaddicted's advice to mean there's no benefit with the NFN28.

 

Quote:
In audio-gd amps high vs low gain is not really a thing, it just changes how many clicks you need to turn to reach an equivalent setting. This leverages all the volume control on the latch relay, which is a very very strong method of attenuation.

Ok thanks. 2 ohm output impedance is a bit high though, for some sensitive headphones.

 

Quote:
But back to Triggaaar i would recommend the NFB-28 for 2 reasons. first it does make a better preamp for monitors (which you want). seconds even if your driving cans with the un-summed single ended output it will be plenty of power plus the option to pick up some flee-bay cables at any time

Why is it a better preamp than the NFB29 - they're basically the same product aren't they? And although the SE output on the 28 is powerful, Audio-GD recommend getting the 29 if you're using SE headphones (I thought because the balanced circuitry in the 28 is better than the SE section of the 28). But if I can get cheap cables on flee bay (UK), I'm good with getting the 28.

 

 

Quote:

Personally i like the 1 box solution for 2, don't think their's any real performance gain and it takes up much more space on your desk. even if you have lots of room and extra money i wouldn't go NFB-1/C2 because you can pick up a used master 11 for not much more.

Thanks. I'm planning to go for a one box solution - NFB28 or 29.

 

Quote:

I'f fed-ex pulls my new NOS 11 out of whatever snow bank they lost it in i'll be selling my NFB-28 (2015) in a week or 2, in case anyone is interested.

Yep :)  What's the difference with the 2015 model?

post #1622 of 1728
Quote:
Originally Posted by MadSounds View Post


I assume you mean if you got a 4 pin > 1/4 inch adapter to attach your SE cables to the nfb-28 balanced out. doesn't really work that way. such a device would most likely only connect to half the amps channels just like the SE output. otherwise this adapter would need more equipment to invert one signal and add it to the other. if such a power summing adapter is available i'm sure it would be more money and hassle then just getting cheap cables.

come to think of it using only half a balanced amp my be harmful some of the amps on the market, but im no expert.


Oh :o

 

In that case, I need cheap balanced cables for the HD650 and HE400i (in the UK) or I should probably get the NFB29.

 

 

 

PS - Does the NFB28 weigh 5kg (that's what it says on the site, I don't know if that includes packaging, if it's a rough estimation, or exact)?


Edited by Triggaaar - 12/24/16 at 6:21pm
post #1623 of 1728

The NFB-28 should ideally only have one-real advantage: common mode noise rejection. That really only matters for long cable runs, as I doubt it's realllly needed internally, especially since the 2015 models where Kingwa put in even more shielding. I'd really like to test it side by side with a 29!

I'm fine having the 28, because the only headphones I use with it are balanced (SE out of the 28 is sub-optimal), and I might want to add studio monitors one day which generally balanced is a better option for.

post #1624 of 1728

PSA: looks like the price was lowered from $750 to $700 (and you can still get the new years 5% discount on top of that for total of $665.00 + shipping).  Prices lowered on other AudioGD stuff too, I just ordered an NFB-1AMP

post #1625 of 1728
Quote:
Originally Posted by djchup View Post
 

PSA: looks like the price was lowered from $750 to $700 (and you can still get the new years 5% discount on top of that for total of $665.00 + shipping).  Prices lowered on other AudioGD stuff too, I just ordered an NFB-1AMP

 

I had to refresh the page. I'm sold at that price, still waiting for them to email me back!

post #1626 of 1728
Quote:
Originally Posted by inertianinja View Post
 

 

I had to refresh the page. I'm sold at that price, still waiting for them to email me back!

Make sure you're getting the auto-reply email from Audio-GD, if you're not you should try a different email address.  I just went though this, took me a week to figure out my email weren't getting through to them.  

post #1627 of 1728
Quote:
Originally Posted by djchup View Post
 

Make sure you're getting the auto-reply email from Audio-GD, if you're not you should try a different email address.  I just went though this, took me a week to figure out my email weren't getting through to them.  

 

I received the automated reply, so I guess I'm just waiting now!

 

BTW, two questions about options:

 

- I'm definitely getting the 2nd set of RCA outs. Can they be set independently to fixed vs. variable?

- The USB upgrade to Amanero - is it correct that this has better compatibility with Windows 10?

post #1628 of 1728

Does anyone happen to know the physical distance between the RCA outs? I'm concerned my cables don't have enough of a split. Thanks.

post #1629 of 1728
Quote:
Originally Posted by phthora View Post
 

Does anyone happen to know the physical distance between the RCA outs? I'm concerned my cables don't have enough of a split. Thanks.

 

about 5.5 inches on the rca out i'm using.

post #1630 of 1728

So my NFB28 arrived and it's been great so far.

 

my *only* complaint with this amp so far: when you have the pre-out set to FIXED, and you press the DAC/HP button to switch from headphone out --> pre-outs, it briefly plays the FULL VOLUME signal through the headphones.

 

My HE500 and LCD3 didn't explode from it, but there are some headphones i would be worried my break. Not a great design quirk.

 

Is it like this for everyone? 

post #1631 of 1728
Quote:
Originally Posted by inertianinja View Post

So my NFB28 arrived and it's been great so far.

my *only* complaint with this amp so far: when you have the pre-out set to FIXED, and you press the DAC/HP button to switch from headphone out --> pre-outs, it briefly plays the FULL VOLUME signal through the headphones.

My HE500 and LCD3 didn't explode from it, but there are some headphones i would be worried my break. Not a great design quirk.

Is it like this for everyone? 

I've never switched between the two while sound was playing. Don't want to, either. biggrin.gif
post #1632 of 1728
Quote:
Originally Posted by inertianinja View Post
 

 

about 5.5 inches on the rca out i'm using.

 

Thanks for the info!

post #1633 of 1728
Quote:
Originally Posted by SodaBoy View Post
 


NFB-28 if you want a quality monolithic unit and don't plan on changing the setup. It has a good form factor and value.

NFB-1AMP is the better amp with lower output impedance and noise, this can be a big deal for IEM guys. NFB-1 combo is good if you like to incrementally upgrade your setup over time..

 

What if I have super sensitive c(iem) but want a "quality monolithic unit and don't plan on changing the setup"? NFB-28 looks like it is what I want but I also would like to use my ciem.

post #1634 of 1728
Quote:
Originally Posted by inertianinja View Post
 

So my NFB28 arrived and it's been great so far.

 

my *only* complaint with this amp so far: when you have the pre-out set to FIXED, and you press the DAC/HP button to switch from headphone out --> pre-outs, it briefly plays the FULL VOLUME signal through the headphones.

 

My HE500 and LCD3 didn't explode from it, but there are some headphones i would be worried my break. Not a great design quirk.

 

Is it like this for everyone? 

 

 

UPDATE - I contacted AGD about this issue and they are sending me a new MCU to swap into my NFB28. We'll see what happens.

post #1635 of 1728
Quote:
Originally Posted by maibuN View Post
 

 

What if I have super sensitive c(iem) but want a "quality monolithic unit and don't plan on changing the setup"? NFB-28 looks like it is what I want but I also would like to use my ciem.

It depends on the impedance of your IEM. A rule of thumb is that optimally, we want a damping factor of >= 8. The damping factor is the ratio between the nominal impedance of a driven load and the output impedance of an amplifier. The NFB-28 has an output impedance of 2 ohms, and if I use the JH13 as an example, it has an impedance of ~28 ohms. That provides a damping factor of 14 which comfortably satisfies requirements. A low damping factor often shifts HP/IEMs towards a warmer signature as bass becomes less controlled.

 

An output impedance of 2 ohms is not bad, and is sufficient for most applications, it's just that 1 ohm output impedance leaves a bigger margin. In my opinion, the output impedance is likely a tradeoff for the non feedback topology of AGD amps. The noise floor on the AGD kit is generally very low, so it should play well enough with high sensitivity low impedance HP/IEMs.

 

If your setup is mostly single ended, you should give the NFB-29 some consideration. I don't understand why it never took off, but it should be just as capable as the NFB-28 for most uses. I don't know your situation, but I only went balanced because I wanted a balanced preamp for a stereo setup that I'm now building (with long cable runs). I'm also a one headphone guy, so I don't have to worry about the costs of rewiring a whole collection of headphones.


Edited by SodaBoy - 1/17/17 at 9:29pm
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Dedicated Source Components
Head-Fi.org › Forums › Equipment Forums › Dedicated Source Components › Audio-gd NFB-28